Aromatic dichlorocyclopropanes



United States Patent 3,341,611 AROMATIC DICHLOROCYCLOPROPANES Ivan C.Popoft, Ambler, and Bernard Loev, Philadelphia, Pa., assignors toPennsalt Chemicals Corporation, Philadelphia, Pa., a corporation ofPennsylvania No Drawing. Original application Mar. 28, 1958, Ser. No.724,527. Divided and this application Sept. 20, 1965, Ser. No. 505,421

2 Claims. (Cl. 260-650) This application is a division of applicationSer. No. 724,527, filed Mar. 28, 1958, and now abandoned.

This invention relates to new compounds containing thedichlorocyclopropyl group I I and certain derivatives of thesecompounds.

Saturated compounds containing the dichlorocyclopropyl group and thecorresponding dibromocyclopropyl group:

such as 1,2-dimethyl-3,3-dichlorocyclopropane Cl Cl or1,Z-dimethyI-S,3-dibromocyclopropane Br Br CH3 C CC H: H H

are known. Compounds of this type are characterized by unusual chemicalinertness. Since they are saturated compounds, however, and contain noreactive substituents they have limited utility since it is difficult toconvezt them to desired derivatives.

A new series of compounds of excellent utility have now been found whichcontain the dichlorocyclopropyl group I I I I group wherein the ..C=O lI group may be either olefinic (that is, having a nonaromatic carbon tocarbon double bond) or may be part of an aromatic ring. The carbons ofthe -dichlorocyclopropyl group are other than those in an aromatic ring.The term aromatic ring as used herein includes carboxylic rings of thebenzene series, including for example benzene, naphthalene, anthraceneetc. and heterocyclic rings of the furan, pyrrole, thiophene .andpyridine series, which in common with those of the benzene series diiierfrom aliphatic unsaturated compounds by their stability to oxidation andtendency to undergo substitution rather than addition reactions.

An especially unique and surprising feature of compounds of this type istheir excellent stability despite the presence of the double bond inneighboring relationship to the dichlorocyclopropyl group. While boththe dichloro-cyclopropyl and the 'dibromo-cyclopropyl compounds in thesaturated series are unusually stable, it has been found surprisinglythat in the presence of a neighboring double bond, only thedichloro-eyclopropyl compounds are stable. The correspondingdibromo-cyclopropyl compounds, such as that prepared by the reaction ofbromoform with butadiene, are often so unstable that they cannot be keptfor more than a brief period before decomposition sets in as evidencedby rapid coloration of the product by liberated bromine. Thecorresponding dibromo compounds thus have little or no utility either inthemselves or as intermedates. For example, while some of the dichlorocompounds of the invention have pharmaceutical uses, such as inneurological applications, the dibromo componds are useless in thisregard because of their rapid decomposition. While the dichlorocompounds of the invention can be subjected to reactions such asoxidation, hydrohalogenation, hydrolysis, nitration, etc. withoutdestroying the dichlorocyclopropyl group, the dibromocyclopropyl groupwill generally undergo rapid decomposition if such reactions areattempted with the corresponding dibromo compounds.

A preferred class of dichlorocyclopropyl compounds of the above generalclass are those in which the double bond neighboring to thedichlorocyclopropyl group is olefinic (i.e. non-aromatic) such as in thefollowing olefins:

and the like. Compounds of this type having from five to 20 carbon atomsare particularly preferred, especially those containing only carbon,hydrogen and chlorine. Particularly preferred among these olefiniccompounds are those in which the dichlorocyclopropyl group is terminalin the molecule; that is, compounds containing a group in which thecarbon to carbon double bond is olefinic (ie is not part of an aromaticring). Compounds 1 to 4 above are particularly preferred compounds ofthis latter type.

These olefinic compounds are particularly valuable in that they mayserve as intermediates for the preparation of derivatives in which afunctional group is introduced into the molecule, particularly where thefunctional group is introduced directly adjacent to the inertdichlorocyclopropyl group. By addition reactions at the olefinic doublebond such as the. addition of H 5 or hydrogen halide, for example, a.mercapto group or halide respectively may be formed adjacent to thedichlorocyclo. propyl group, or by oxidation, an aldehyde or acid groupmay be formed at the double bond with accompanying cleavage at thispoint. For example, by oxidation of compounds such as acids such as maybe formed. Such derivatives, and their preparation are described in moredetail hereinafter.

Another class of dichlorocyclopropyl compounds within the scope of theinvention are those in which the double bond neighboring of thedichlorocyclopropane group is a double bond in a carbocylic aromaticring (that is part of a carbocyclic aromatic ring) such as in thefollowing compounds:

CH=CH1 The last compound (14) it will be noted contains both aromaticand olefinic unsaturation neighboring to the dichlorocyclopropyl group.

These aromatic compounds having the inert dichlorocyclopropyl groupattached directly to the aromatic group can be converted to valuablederivatives by subjecting the compound to the usual reactions of whichan aromatic ring is susceptible such as sulfonation, nitration,alkylation, halogenation, and the like.

Still another class of dichlorocyclopropyl compounds within the scope ofthe invention are those in which the double bond neighboring to thedichlorocyclopropyl group is a double bond in a heterocyclic aromaticring (that is, part of a heterocyclic aromatic ring) such as in thefollowing compounds: (a heterocycl ic aromatic ring refers to a ring ofthe furan, pyrrole, pyridine or thiophcne series).

The latter heterocyclic compounds containing the inertdichlorocyclopropyl group attached directly to the heterocyclic ring maybe subjected to most of the usual reactions undergone by thesehetercyclic systems without affecting the inert dichlorocyclopropylgroup.

Any of the above compounds and in general any of the compounds of theinvention may contain various substituent groups. These may have beenpresent in the original olefin from which the dichlorocyclopropylcompound is formed, or may be formed after the dichlorocyclopropyl groupis introduced. Thus, relatively inert substituents such as alkoxy,alkylmercapto, chloro, dialkylamino and similar substituents may bepresent in the original olefin from which the dichlorocyclopropylcompound is formed while relatively reactive substituents such as nitro,carboxy, amino and the like may be introduced after the formation of thedichlorocyclopropyl compound.

The new compounds of the invention may be prepared by reactingchloroform, CHCL with a compound containing conjugated carbon to carbondouble bonds in which at least one of the conjugated double bonds isolefinic in character (that is, not a part of an aromatic ring). Thus,conjugated diolefins, such as butadiene, isoprene, or piperylene, orl-ethylbutadiene may be reacted with chloroform to form compounds (1),(2), (3), (4), respectively. Non-aromatic cyclic diolefins, such ascyclopentadiene, butylcyclopentadiene, or 1,3-cyclohexadiene may bereacted with the chloroform to form compounds (5), (6) and (7)respectively, as given above. Also, compounds in which an olefinicdouble bond is conjugated with an aromatic double bond such as vinylsubstituted aromatic compounds may be reacted with chloroform to providenew compounds according to the invention. Thus, styrene, divinylbenzene,vinylnaphthalene, 3-methoxy-2- (l-propenyl) naphthalene,diphenylethylene or 4-phenyl- 1-3-butadiene, may be reacted withchloroform to give the above compounds (9), (10), (ll), (l2), (l3) and(14) respectively. Furthermore, heterocyclic compounds of the aromatictype, such as vinylpyridine, divinylthiophene, or vinylfuran may bereacted with chloroform to give the above compounds (l4), (l5), (l6) and(17).

The reaction should be carried out in the presence of an alkali metalalkoxide such as potassium tertiary butoxide, sodium methoxide, orpotassium tertiary-amylate. The preferred alkali metal alkoxide ispotassium tertiary butoxide. For best results the reaction should becarried out under anhydrous conditions.

The solvent for the reaction may be an alcohol, and preferably analcohol corresponding to the alkali metal alkoxide, particularlytertiary butyl alcohol. Excess chloroform may also be employed as thesolvent. Under some circumstances, other inert solvents may be employedsuch as, benzene, diethyl ether, dioxane, petroleum ether and the like.

The reaction is generally carried out over the temperature range of from-50 C. to +100? C. although lower temperatures can be used whererequired in the handling of low boiling compounds. The preferredtemperature range is 20 C. to +40 C. The reaction may be carried out atsub-atmospheric, atomspheric or super-atmospheric pressures, although inmost instances the reaction is readily carried out at atmosphericpressures, and atmospheric pressures are accordingly preferred.

The starting olefin may contain such relatively inert functional groupsas alkoxy, chloromethyl, alkylmercapto, chloro, dialkylamino, and thelike which do not react under the above reaction conditions. Forexample, the reaction may be carried out using as the starting olefinanethole, 1,4 divinyl 2 dimethylamino benzene, 1- ethylmercapto 2vinylnaphthalene, l-vinyl 4-chloronaphthalene, 6-butoxy-l,3-rexadieneand the like. Substituents such as amino (NI-I acyl halide, carboxy(COOH) or the like which might react under the above reaction conditionsshould not generally be present in the starting olefin. As explainedabove, these may be introduced into the dichlorocyclopropyl compoundafter its formation.

In a typical reaction procedure, anhydrous chloroform is gradually addedto a suspension of potassium bu-toxide in a solution of the olefin intertiary butyl alcohol at from 5 to +10 C. After the addition, stirringis continued for about an additional hour and the product is worked upby usual procedures. In some instances it is preferable to reverse theprocedure by gradually adding a suspension of the alkoxide in thecorresponding alcohol to a solution of the olefin in chloroform.

While the invention does not depend upon any particular explanation ofthe mechanism of the reaction, it is believed that the reaction proceedsthrough a dichloro carbene (:CCl intermediate as follows:

According to Equation 1, in the presence of the alkoxide (RO) thetrichloromethylcarbanion (CCI is formed. This further dissociates into achloride ion (Cl) and dichlorocarbene (:CCI (Equation 2). Thedichlorocarbene then adds across the olefinic double bond to form thedichlorocyclopropyl group.

Assuming the above mechanism, it would not be possible to predictwhether a 1,2- or a l,4-addition to a conjugated diolefin would occur toform a cyclopropyl or a cyclopentenyl ring respectively. However, it hasbeen determined that the 1,2-addition takes place to the substantialexclusion of the l,4-addition to form the dichlorocyclopropyl ring asillustrated in the above equations.

EXAMPLE 1 A suspension of 366 grams (3.27 moles) of KOC(CH in 148 grams(2.0 moles) of HOC(CH 3000 ml. of diethyl ether, and 900 grams (16.65moles) of bu-tadiene is placed in a 4 neck flask equipped with astirrer, thermometer well, dropping funnel, and Dry Ice condenserequipped with a CaCl drying tube. The flask and contents is cooled downto 5 C. Over a period of 1.5 hours there is added slowly 490 grams (4.1moles) of chloroform (CHCl while stirring and while keeping the reactiontemperature at 3 C. to 0" C. The reaction mixture is stirred for anadditional hour at 0 C. to 5 C. and for another hour at 5 C. to 10 C.

The Dry Ice condenser is replaced with a fractionating column and theexcess butadiene is distilled oil. The residue is filtered and thefiltrate fractionated.

There is obtained 188 grams (60% yield based on unrecovered CHCl of1,1-dichloro-2 vinylcyclopropane having a boiling point of C. at 760 mm.Hg, a refractive index r1 1.4720. Infrared analysis of this productshows the bands characteristic of the cyclopropyl and the vinyl groups.The compound was analyzed as follows:

Calculated: 43.7% C, 4.37% H, 51.8% C1. Found: 43.8% C, 4.79% H, and50.8% C1.

In addition to the 1,1-dichloro-2-vinylcyclopropane there is obtained17.5 grams of a high boiling material which is shown to be2-(2,2'-dichlorocyclopropyl)-1,1- dichlorocyclopropane 7 EXAMPLE 2 Usingthe procedure described in Example 1, 2.5 moles of chloroform wasreacted with 6 moles of isoprene in the presence of 2 moles of KOC(CHThe product is worked up as described in Example 1 to give a yield ofabout 45% based on unrecovered oi or 015101: of CF -CCH=CH2 along withminor amounts of CHz=CC I- CH2.

Upon infrared analysis, these products show the characteristiccyclopropyl and vinyl absorption bands.

EXAMPLE 3 In a four necked flask equipped as in Example 1, there isplaced a solution of 650 grams (5 moles) of commercial gradedivinylbenzene in 240 grams (2 moles) of CHCl The divinylbenzene is amixture having a narrow boiling range and containing the variousdivinylbenzene isomers (predominantly ortho and meta with some para) aswell as some ethyl vinylbenzene. The flask and contents are chilled and250 grams (2 moles) of a suspension of potassium tertiary amylate inhexane is gradually added to the chilled solution. The reactiontemperature is maintained at C. by means of a cooling bath. After theaddition is complete, the reaction is stirred another hour at 15 C. andovernight at C. The salt (KCl) is filtered off, and the solution is thenwashed with water, dried and distilled in vacuo.

After removal of the unreacted divinylbenzene and ethyl vinylbenzene, afraction is obtained consisting of the various isomers (predominantlyortho and para) of (2,2-dichlorocyclopropyl) -vinylbenzene HzC CH CH=CH2and (2,2-dichlorocyclopropyl)-ethy1benzene followed by a higher boilingproduct consisting of a mixture of the various isomers (i.e., the ortho,meta and para) of bis-(2,2-dichlorocyclopropyl) benzene This lattermaterial forms a glass when cooled in a dry ice-acetone bath.

EXAMPLE 4 addition which requires 3 hours. Following the addition, thereaction mixture is stirred an additional hour and then poured intowater.

The organic layer is separated, dried and the solvent and unreactedolefin removed, leaving a semi-solid which is recrystallized fromacetone to give a solid product having the structure3-methoxy-2-(2,2-dich1oro-3-methylcyclopropyl)naphthalene V OCHa EXAMPLE5 A suspension of 1 mole of potassium tertiary butoxide in ether isadded solwly to a mixture of 2 moles of 3- vinylthiophene and 2 moles ofchloroform while maintaining the reaction mixture at 0 C. during theaddition. Stirring was continued for an additional several hours at 10C. The product was worked up and isolated in the same manner asdescribed in Example 3. The product,3-(2,2-dichlorocyclopropyl)-thiophene is a stable liquid.

The compounds of the invention have utility in themselves as herbicides,insecticides, particularly as fumigants; bactericides, lubricants,plasticizers, lube oil additives and pharmaceuticals. The compound1,1-dich1oro-2- vinylcyclopropane, for example, has been shown to haveneurological activity. These compounds, particularly 1,1-dichloro-2-vinylcyclopropane may also serve as monomers for thepreparation of high molecular weight polymers having good flameresistance due to the presence of the dichlorocyclopropyl group.

The compounds of the invention in which the double bond adjacent to thedichlorocyclopropyl group is olefinic in character are particularlyuseful as starting materials for the formation of derivatives byintroduction of a carboxyl, aldehyde or hydroxyl group in a positiondirectly adjacent to the inert dichlorocyclopropyl group. These types ifreactions proceed in general as follows:

In Equation 4 oxidation to the acid is illustrated. Cleavage occurs atthe double bond neighboring to the dichlorocyclopropyl group with aformation of the carboxyl group at this point. Equation 5 illustratesthe formation of the aldehyde which also involves cleavage at theneighboring double bond with the formation of the aldehyde. By reductionof the aldehyde in the usual manner the corresponding alcohol may beformed.

I The oxidation to the acid may be readily carried out by use ofstandard oxidizing agents, such as potassium permanganate or potassiumdichromate. A particularly advantageous method of oxidation involves theuse of ozone to form an ozonide at the double bond. The ozonide, ontreatment with hydrogen peroxide, gives the corresponding acid. Thisreaction may be illustrated in the case of the compound1,1-dichloro-2-vinylcyclopropane as follows:

In the case of the compound (2,2-dichlorocyclopropyl) vinyl benzene thisreaction may be illustrated as follows:

C\-CH2 /C\-CH2 C C 01 CE 03 2 2 l [ozonide] I l CH=CHa 00011 Thealdehyde may also be produced from the ozonide by catalytichydrogenation of the latter using a platinum on charcoal catalyst. Inthe case of the compound 1,1- dichloro-Z-vinylcyclopropane, thisreaction may be illustrated as follows:

An alternative method of synthesis of the aldehyde involves theformation of the glycol as an intermediate. The glycol may be preparedby oxidation of the double bond by OsO by the use of performic acid, orby the use of silver iodobenzoate (Preevost reagent) and the like. Theglycol may be oxidized to the aldehyde by the use of H leadtetraacetate, etc. This example of synthesis of the aldehyde may beillustrated, in the case of the compound1,l-dichloro-2-vinylcyclopropane, using a performic acid catalyst toform a glycol, followed by oxidation of the glycol with leadtetraacetate, as follows:

2 NaOH o o OH on c1 01 c1 c1 (10 Pb(0Ac)4 on. CHCHCH1 03 01141110 o onon o 01 c1 c1 01 It will be noted that the formation of the acids,alde-- hydes and alcohols in the manner described above results in theintroduction of the functional group, (that is the carboxyl, aldehyde orhydroxyl group respectively) directly adjacent to thedichlorocycloproply ring without any intervening methylene (CH groups.Compounds of this type, particularly where the dichlorocyclopropyl groupis terminal in the molecule, such as in Cl Cl are particularly valuablebecause they provide the combination of a reactive functional groupattached directly to the inert dichlorocyclopropyl group. By further reaction of the acid, aldehyde or alcohol, it is then possible tointroduce the dichlorocyclopropyl group into other molecules withoutintervening methylene groups which might otherwise represent a weakpoint. For example, the acid CH2CH-COOH may be employed to acylatecotton or cellulose to provide 7 flame resistance and increased chemicalstability.

EXAMPLE 6 at 40 C. The resulting ozonide solution is refluxed with 35%hydrogen peroxide. The solvent and water are then removed by vacuumdistillation. The residual viscous oil slowly crystallizes. Afterrecrystallization from a benzene-ligroin mixture, the product2,2-dichloro-l-cyclopropanecarboxylic acid o1\ Cl Cr-CH-C o 0 H has amelting point of about 77 C.

EXAMPLE 7 Gabon-Q0 0 OH Cl Cl EXAMPLE 8 A solution of 10 grams of1,l-dichloro-Z-vinylcyclopropane in ethyl acetate is ozonized asdescribed in Ex ample 6. The ozonide is then catalytically reduced undera slight hydrogen pressure using about 0.1 gram of palladium on-charcoalhydrogenation catalyst containing approximately 5% palladium. Thesolvent is stripped off by vacuum distillation and the aldehyde2,2-dichloro-1- cyclopropane aldehyde is steamed distilled and may beisolated from the distillate as the methone derivative.

EXAMPLE 9 The aldehyde prepared as in Example 8 is dissolved in aceticacid and hydrogenated over a period of 3 hours using a platinumon-charcoal hydrogenation catalyst containing about 5% platinum. Thealcohol, l-hydroxymethyl-2,Z-dichlorocyclopropane CH2CHCHaOH c1 c1 isisolated from the reaction mixture by vacuum distillation.

Difunctional acids, aldehydes, amines, and the like containing thedichlorocyclopropyl group may be prepared for example by oxidation of acycloaliphatic dichlorocyclopropyl containing compound such as H C1 C CHor the'corresponding dialdehyde. By well known methods, the diacid maybe converted to the diamine or the dialdehyde converted to thedialcohol. Such difunctional compounds are useful intermediates forcondensation reactions to give polyesters (by reaction of the diacid anddialcohol), polyamides (by reaction of the diacid and diamine) and thelike containing the inert dichlorocyclopropyl group.

The compounds of the invention which contain an olefinic double bond inaddition to the dichlorocyclopropyl group are also useful in that theolefinic double bond may undergo various addition reactions to introducefunctional groups such as mercapto, halo, hydroxy, amino, epoxy, and thelike.

Thus, for example hydrogen sulphide and mercaptans may be added to thedouble bond either in the normal (Markownikolf) manner or in theabnormal (anti- Markownikoff) manner, to provide a mercapto group on thecarbon atom directly adjacent to, or on the carbon atom next adjacentto, the dichlorocyclopropyl group. The abnormal addition may becatalyzed by free radical initiators such as peroxides or ultra violetlight. The normal addition may be catalyzed by acids. Equation 11 belowillustrates the normal addition, while Equation 12 illustrates theabnormal addition of hydrogen sulphide and mercapt-ans to the compoundl,1-dichloro-2-vinylcyclopropane:

where R may be an organic radical, such as alkyl, or hydrogen.

When H S is used, the product may be either a mercaptan or a sulphide ora mixture, depending upon the ratio of H 8 to olefin, the higher ratiosof H 8 to olefin tending to give the mercapt-an as the major product.

Hydrogen halides can also be added in either the normal (Equation 13) orabnormal (Equation 14) manner, these addition reactions beingillustrated in the case of HBr and the compound1,1-dichloro-2-viny-lcyclopropane as follows:

C Br

C C or C1 C1 c1 The double bond will also react with halogens in thenormal manner to give vicinal dihalides, this reaction being illustratedin the case of chlorine and l,1-dichloro-2- vinylcyclopropane asfollows:

o Cl Cl (:1 Cl Cl Cl These olefinic compounds may undergo other additionreactions typical of simple olefins. For example, an alcohol may beformed by first forming the sulphuric acid ester followed by hydrolysisof the ester to the alcohol. Oxygen may be added at the double bond togive ethylene oxide type derivatives, (most conveniently by reactionwith a peracid): hypohalous acids e.g. hypochlorous, as well asbisulfites, ammonia, amines, and phenols may also be added by standardtechniques. The double bond may also be reduced by catalytichydrogenation.

The following examples illustrate respectively the addition of hydrogensulphide, a mercaptan, a hydrogen halide and a halogen.

12 EXAMPLE l0 l,l-dichloro-2-vinylcyclopropane is placed in a quartztest tube and cooled to 0 C. Hydrogen sulphide is bubbled through t-hecompound while it is maintained at this temperature. A 350 wattultra-violet light is placed close to the test tube during the reaction.At the end of about two hours, the liquid in the test tube consists of amixture of the unreacted starting olefin, 2-(2,2-dichlorocyclopropy-l)ethanethiol-l.

CHz-CH-CHzCH SH C Cl Cl and 2-(2,2-dichloroc-yclopropyl)-ethyl sulphideWhen the reaction is carried out under pressure and with an acidcatalyst, such as phosphoric acid on kieselguhr, the secondarymercaptan,

/C SH 01 Cl and sulfide,

CHrCH2CH-CHS.

o J or Cl 2 result.

EXAMPLE 11 An equimolar mixture of 1,l-dichlorQ-Z-vinylcyclopropane andnormal-propyl mercaptan and 10% by weight (based on the reactants) ofphosphoric acid is placed in an autoclave and heated to C., whilestirring, under 50 grams of 1,1-dichloro-Z-vinylcyclopropane isdissolved in 100 ml. of glacial acetic acid. While the solution ismaintained at 25 C. gaseous hydrogen chloride is passed therethrough for4 hours with stirring. The resulting productl-(l-chloroethyl)-2,2-dichlorocyclopropane,

CHnCHg-CHCH3 l /C\ Cl Cl Cl is isolated by vacuum distillation.

EXAMPLE 13 Equal volumes of 1,1-dichloro-2-vinylcyclopropane and carbontetrachloride are placed in a flask and maintained at 0 C. Gaseouschlorine is passed through the solution until no further gain in weightis noted. The solvent and dissolved chlorine are removed by distillationin vacuo to obtain the product1-(1,2-dichloroethyl)-2,2-dichlorocyclopropane,

$1 (Ill 1110 CH-CHCH2.

Another valuable derivative that may be obtained from the compounds ofthe invention which contain an olefinic double bond are those in whichanother dichlorocarbon (:CCI is added to the double bond to form abis(dichlorocyclopropyl) derivative. Derivatives of this type may beformed .by further reacting the olefin containing dichlorocyclopropylcompounds of the invention with chloroform under the same reactionconditions described above to introduce the second dichlorocyclopropylgroup. Alternatively, and more conveniently, thebis(dichlorocyclopropyl) derivatives may be prepared by reacting aconjugated diolefin such as butadiene, isoprene divinyl benzene etc.with an excess of chloroform and the alkali metal alkoxide. If both thechloroform and alkali metal alkoxide are bot-h present in relativelylarge excess, the bis(dichlorocyclopropyl) compound will be thepredominant product. Other conditions as described above may be thesame. This latter reaction is illustrated by the following exampleemploying butadiene and an excess of chloroform and alkali metalalkoxide.

EXAMPLE 14 A suspension of 366 grams of KOC(CH in 148 grams of HOC(CH300- ml. of diethyl ether, and 108 grams (2.0 moles) of butadiene iscooled to 5 C. 490 grams of chloroform is added slowly to the mixtureover a period of 1 /2 hours while stirring and keeping the reactiontemperature at about C. The reaction mixture is stirred for anadditional hour at this temperature and for another hour at atemperature of about to C.

Excess chloroform is distilled 01f under vacuum. The residue is filteredand the filtrate fractionated to obtain a yield of about 40% (based onbutadiene) of the bis(dichlorocyclopropyl) compound 2-(2,2-dichlorocyclopropyl) 1,l-dichlorocyclopropane,

and about a 10% yield of the mono-dichlorocyclopropyl compound1,l-dichloro-2-vinylcyclopropane.

The bis(dichlorocyclopropyl) compounds are useful as herbicides,insecticides, particularly as fumigants, plasticizers, lube oiladditives and the like.

We claim:

1. An aromatic dichlorocyclopropane having the formula radical and n is1 when Ar is a fused ring.

2. p-Di-(2,2-dichlorocyclopropyl) benzene having the formula H H H H 1 ll I C/O-H C--Cl 0-01 6. $1

References Cited UNITED STATES PATENTS 3,012,079 12/1961 Bruson et al.

LEON ZITVER, Primary Examiner.

N. J. KING, H. T. MARS, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,341,611 September 12, 1967 Ivan C Popoff et a1 It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 3, line 65, for "of" read to column 4, structure (11) for theupper 1eft-hand portion reading H C CH- H C CH- column 5, line 72, for"rexadiene" read hexadiene column 8, line 18, for "solwly" read slowlycolumn 8, line 42, for "if" read of same column 8, structure (6), forthat portion of the structure reading 0 ead O r column 9, line 49, for"dichlorocycloproply" read dichlorocyclopropyl column 11, structure (13)the left-hand portion of the structure should appear as shown belowinstead of as in the patent:

cH --cH-cH=cH +HBr i Signed and sealed this 17th day of September 1968.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. EDWARD J. BRENNER Attesting Officer Commissionerof Patents

1. AN AROMATIC DICHLOROCYCLOPROPANE HAVING THE FORMULA 2.P-DI-(2,2-DICHLOROCYCLOPROPYL) BENZENE HAVING THE FORMULA